Аннотация:The application of carbon nanoparticles as modifiers of polyepoxyurethane-containing isocyanurates results in achieving the highest increase in physicochemical properties even when they have a low content in the composition. Impact number A at nanocarbon weight content W of 0.5% is almost 1.5 times higher than that of the matrix polymer. The obtained dependence of the impact number on the weight content A = (W) for the considered nanocomposite samples has an extremum pattern, where the maximum is achieved at W = 0.5%. At W = 0.5%, elasticity modulus Ecomp of the composite (in compression tests) increased almost 1.3-fold compared to the starting polymer.